Python: Cannot concatenate str and NoneType objects

Question

sql = """
        INSERT INTO [SCHOOLINFO] 
        VALUES(
            '""" + self.accountNo + """', 
            '""" + self.altName + """',
            '""" + self.address1 + """',
            '""" + self.address2 + """',
            '""" + self.city + """',
            '""" + self.state + """',
            '""" + self.zipCode + """',
            '""" + self.phone1 + """',
            '""" + self.phone2 + """',
            '""" + self.fax + """',
            '""" + self.contactName + """',
            '""" + self.contactEmail + """',
            '""" + self.prize_id + """',
            '""" + self.shipping + """',
            '""" + self.chairTempPass + """',
            '""" + self.studentCount + """'
        )
    """;

I have the following code and Python keeps throwing the error that it cannon concatenate strings and nonetype objects. The thing is I have verified every variable here is in fact a string and is not null. I have been stuck on this for quite some time today, and any help would be greatly appreciated.

Answer 1

Use bind variables instead. Here's the spec for working with DBs in Python: PEP 249: Python Database API Specification v2.0.

UPDATE: Based on the docs for pymssql, you need something like:

sql = """
    INSERT INTO [SCHOOLINFO] 
    VALUES(
        %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %d, %s, %s, %d
    )"""
cur.execute(sql, self.accountNo, self.altName, self.address1, self.address2, self.city, self.state, self.zipCode, self.phone1, self.phone2, self.fax, self.contactName, self.contactEmail, self.prize_id, self.shipping, self.chairTempPass, self.studentCount)

Answer 2

All these answers so far focus not on your problem but on what is right to do. Yes, yes - bind variables is better and safer. And yes, using % for formatting is faster and likely better.

But on your question what gives you that error - it must be that one of the values is None at some point, there is no other explanation. Just put a debug print in front of that, something like:

for v in 'accountNo altName address1 address2 city state zipCode phone1 phone2 fax contactName contactEmail prize_id shipping chairTempPass studentCount'.split():
    if getattr(self, v) is None:
        print 'PANIC: %s is None' % v

I bet it will print something at some point ;-)